While our speaker never tells us much about himself directly (in fact we're just guessing he's a he, since we have no evidence to the contrary), we learn a lot about him from the way he puts the story of "Evangeline" down on paper. Here's a list of the things we can say about him:
1. Dude is long-winded. We mean, come on, 1400 lines? We've seen this exact same story told in a two-sentence "Missed Encounters" Craigslist post (not that we make a habit of logging on there or anything…). The story of the poem itself is actually pretty straightforward: girl meets boy, girl loses boy, girl looks all over for boy, girl finds boy but it's too late because he dies. So what's up with all the words? Why spend so much time and effort to bring us this tale? Well, most of those words are spent giving us a detailed—and we mean detailed—account of life at this time, in Acadia, in Louisiana, and in the parts in between. We learn about the different kinds of livestock the farmers had, what kind of tobacco they smoked, what sort of trees and plants they encountered. Their life experiences are given our speaker's full attention, and that's because he's really trying to drive home what it was life for these poor exiles, forced from their comfy homes and thrust into a strange new world.
2. Dude knows his Bible. You can check out "Shout Outs" for a full list, but for now it's enough to say that this guy is handy with a Biblical allusion—or twelve. It seems like he's got a Christian reference in mind for nearly everything that happens in the story. This, of course, gives us a sense that our speaker knows his Bible, back to front and inside out. What's more, it hints at the speaker's motivation for telling us this story in the first place. He's portraying these characters as models of faithful, pious behavior. Evangeline, in particular, never waivers from her belief in God—despite all the hardships she has to endure. By making her the poem's hero, our speaker is underscoring the importance of religious (specifically Christian, and even more specifically Catholic) faith.
3. Dude knows his poetry. As we mention in "Form and Meter," Longfellow was very consciously following in the classical footsteps of epic poets like Homer and Virgil. In fact, the only time our speaker refers to himself in the poem is to bust out a very classical appeal for inspiration:
Let me essay, O Muse! to follow the wanderer's footsteps;—
Not through each devious path, each changeful year of existence,
But as a traveller follows a streamlet's course through the valley: (732-734)
This appeal to the Muse—a mythical source of artistic (in this case poetic) inspiration—is called an apostrophe, and it's a page right out of the classical, epic poem playbook. He's working hard to elevate this tale from merely a sad love story to a sweeping, epic tragedy. What do you think—did he succeed?